[BUG] Attempt to send a notification via SES sender causes fatal error on v3.1.0

[ikorchynskyi]

What is the bug?

Attempt to send a notification via SES sender causes fatal error on Opensearhc v3.1.0:

{"type": "server", "timestamp": "2025-07-19T16:28:11,490Z", "level": "ERROR", "component": "o.o.b.OpenSearchUncaughtExceptionHandler", "cluster.name": "opensearch-cluster", "node.name": "opensearch-node", "message": "fatal error in thread [DefaultDispatcher-worker-1], exiting", "cluster.uuid": "idtMdBc8QAS3pM-h5M795w", "node.id": "NKrKnKlsTl27Cjw_phJoEA" ,
"stacktrace": ["java.lang.NoClassDefFoundError: Could not initialize class com.amazonaws.http.AmazonHttpClient",
"at com.amazonaws.AmazonWebServiceClient.<init>(AmazonWebServiceClient.java:236) ~[aws-java-sdk-core-1.12.687.jar:?]",
"at com.amazonaws.AmazonWebServiceClient.<init>(AmazonWebServiceClient.java:225) ~[aws-java-sdk-core-1.12.687.jar:?]",
"at com.amazonaws.services.securitytoken.AWSSecurityTokenServiceClient.<init>(AWSSecurityTokenServiceClient.java:299) ~[aws-java-sdk-sts-1.12.687.jar:?]",
"at com.amazonaws.services.securitytoken.AWSSecurityTokenServiceClient.<init>(AWSSecurityTokenServiceClient.java:285) ~[aws-java-sdk-sts-1.12.687.jar:?]",
"at com.amazonaws.services.securitytoken.AWSSecurityTokenServiceClientBuilder.build(AWSSecurityTokenServiceClientBuilder.java:61) ~[aws-java-sdk-sts-1.12.687.jar:?]",
"at com.amazonaws.services.securitytoken.AWSSecurityTokenServiceClientBuilder.build(AWSSecurityTokenServiceClientBuilder.java:27) ~[aws-java-sdk-sts-1.12.687.jar:?]",
"at com.amazonaws.client.builder.AwsSyncClientBuilder.build(AwsSyncClientBuilder.java:46) ~[aws-java-sdk-core-1.12.687.jar:?]",
"at org.opensearch.notifications.core.credentials.oss.CredentialsProviderFactory.getCredentialsProviderByIAMRole(CredentialsProviderFactory.kt:30) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"at org.opensearch.notifications.core.credentials.oss.CredentialsProviderFactory.getCredentialsProvider(CredentialsProviderFactory.kt:20) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"at org.opensearch.notifications.core.credentials.oss.SesClientFactoryImpl.createSesClient$lambda$0(SesClientFactoryImpl.kt:19) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"at java.base/java.security.AccessController.doPrivileged(AccessController.java:571) ~[?:?]",
"at org.opensearch.notifications.core.utils.SecurityAccess.doPrivileged(SecurityAccess.kt:25) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"at org.opensearch.notifications.core.credentials.oss.SesClientFactoryImpl.createSesClient(SesClientFactoryImpl.kt:17) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"at org.opensearch.notifications.core.client.DestinationSesClient.sendMimeMessage(DestinationSesClient.kt:88) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"at org.opensearch.notifications.core.client.DestinationSesClient.execute(DestinationSesClient.kt:74) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"at org.opensearch.notifications.core.transport.SesDestinationTransport.sendMessage(SesDestinationTransport.kt:43) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"at org.opensearch.notifications.core.transport.SesDestinationTransport.sendMessage(SesDestinationTransport.kt:23) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"at org.opensearch.notifications.core.NotificationCoreImpl.sendMessage$lambda$0(NotificationCoreImpl.kt:38) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"at java.base/java.security.AccessController.doPrivileged(AccessController.java:319) ~[?:?]",
"at org.opensearch.notifications.core.NotificationCoreImpl.sendMessage(NotificationCoreImpl.kt:35) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"at org.opensearch.notifications.send.SendMessageActionHelper.sendMessageThroughSpi(SendMessageActionHelper.kt:598) ~[?:?]",
"at org.opensearch.notifications.send.SendMessageActionHelper.sendEmailFromSesAccount(SendMessageActionHelper.kt:566) ~[?:?]",
"at org.opensearch.notifications.send.SendMessageActionHelper.access$sendEmailFromSesAccount(SendMessageActionHelper.kt:63) ~[?:?]",
"at org.opensearch.notifications.send.SendMessageActionHelper$sendEmailMessage$1$statusDeferredList$1$1.invokeSuspend(SendMessageActionHelper.kt:479) ~[?:?]",
"at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33) [kotlin-stdlib-1.9.25.jar:1.9.25-release-852]",
"at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106) [kotlinx-coroutines-core-jvm-1.4.3.jar:?]",
"at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:571) [kotlinx-coroutines-core-jvm-1.4.3.jar:?]",
"at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:750) [kotlinx-coroutines-core-jvm-1.4.3.jar:?]",
"at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:678) [kotlinx-coroutines-core-jvm-1.4.3.jar:?]",
"at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:665) [kotlinx-coroutines-core-jvm-1.4.3.jar:?]",
"Suppressed: java.lang.NoClassDefFoundError: Could not initialize class com.amazonaws.http.AmazonHttpClient",
"\tat com.amazonaws.AmazonWebServiceClient.<init>(AmazonWebServiceClient.java:236) ~[aws-java-sdk-core-1.12.687.jar:?]",
"\tat com.amazonaws.AmazonWebServiceClient.<init>(AmazonWebServiceClient.java:225) ~[aws-java-sdk-core-1.12.687.jar:?]",
"\tat com.amazonaws.services.securitytoken.AWSSecurityTokenServiceClient.<init>(AWSSecurityTokenServiceClient.java:299) ~[aws-java-sdk-sts-1.12.687.jar:?]",
"\tat com.amazonaws.services.securitytoken.AWSSecurityTokenServiceClient.<init>(AWSSecurityTokenServiceClient.java:285) ~[aws-java-sdk-sts-1.12.687.jar:?]",
"\tat com.amazonaws.services.securitytoken.AWSSecurityTokenServiceClientBuilder.build(AWSSecurityTokenServiceClientBuilder.java:61) ~[aws-java-sdk-sts-1.12.687.jar:?]",
"\tat com.amazonaws.services.securitytoken.AWSSecurityTokenServiceClientBuilder.build(AWSSecurityTokenServiceClientBuilder.java:27) ~[aws-java-sdk-sts-1.12.687.jar:?]",
"\tat com.amazonaws.client.builder.AwsSyncClientBuilder.build(AwsSyncClientBuilder.java:46) ~[aws-java-sdk-core-1.12.687.jar:?]",
"\tat org.opensearch.notifications.core.credentials.oss.CredentialsProviderFactory.getCredentialsProviderByIAMRole(CredentialsProviderFactory.kt:30) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"\tat org.opensearch.notifications.core.credentials.oss.CredentialsProviderFactory.getCredentialsProvider(CredentialsProviderFactory.kt:20) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"\tat org.opensearch.notifications.core.credentials.oss.SesClientFactoryImpl.createSesClient$lambda$0(SesClientFactoryImpl.kt:19) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"\tat java.base/java.security.AccessController.doPrivileged(AccessController.java:571) ~[?:?]",
"\tat org.opensearch.notifications.core.utils.SecurityAccess.doPrivileged(SecurityAccess.kt:25) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
fatal error in thread [DefaultDispatcher-worker-1], exiting
"\tat org.opensearch.notifications.core.credentials.oss.SesClientFactoryImpl.createSesClient(SesClientFactoryImpl.kt:17) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"\tat org.opensearch.notifications.core.client.DestinationSesClient.sendMimeMessage(DestinationSesClient.kt:88) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"\tat org.opensearch.notifications.core.client.DestinationSesClient.execute(DestinationSesClient.kt:74) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"\tat org.opensearch.notifications.core.transport.SesDestinationTransport.sendMessage(SesDestinationTransport.kt:43) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"\tat org.opensearch.notifications.core.transport.SesDestinationTransport.sendMessage(SesDestinationTransport.kt:23) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"\tat org.opensearch.notifications.core.NotificationCoreImpl.sendMessage$lambda$0(NotificationCoreImpl.kt:38) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"\tat java.base/java.security.AccessController.doPrivileged(AccessController.java:319) ~[?:?]",
"\tat org.opensearch.notifications.core.NotificationCoreImpl.sendMessage(NotificationCoreImpl.kt:35) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"\tat org.opensearch.notifications.send.SendMessageActionHelper.sendMessageThroughSpi(SendMessageActionHelper.kt:598) ~[?:?]",
"\tat org.opensearch.notifications.send.SendMessageActionHelper.sendEmailFromSesAccount(SendMessageActionHelper.kt:566) ~[?:?]",
"\tat org.opensearch.notifications.send.SendMessageActionHelper.access$sendEmailFromSesAccount(SendMessageActionHelper.kt:63) ~[?:?]",
"\tat org.opensearch.notifications.send.SendMessageActionHelper$sendEmailMessage$1$statusDeferredList$1$1.invokeSuspend(SendMessageActionHelper.kt:479) ~[?:?]",
"\tat kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33) [kotlin-stdlib-1.9.25.jar:1.9.25-release-852]",
"\tat kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106) [kotlinx-coroutines-core-jvm-1.4.3.jar:?]",
"\tat kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:571) [kotlinx-coroutines-core-jvm-1.4.3.jar:?]",
"\tat kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:750) [kotlinx-coroutines-core-jvm-1.4.3.jar:?]",
"\tat kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:678) [kotlinx-coroutines-core-jvm-1.4.3.jar:?]",
"\tat kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:665) [kotlinx-coroutines-core-jvm-1.4.3.jar:?]",
"Caused by: java.lang.ExceptionInInitializerError: Exception java.lang.NoClassDefFoundError: org/apache/http/conn/routing/HttpRoutePlanner [in thread \"DefaultDispatcher-worker-2\"]",
"\tat com.amazonaws.http.AmazonHttpClient.<clinit>(AmazonHttpClient.java:165) ~[?:?]",
"\t... 30 more",
"Suppressed: java.lang.NoClassDefFoundError: org/apache/http/conn/routing/HttpRoutePlanner",
"\tat com.amazonaws.http.AmazonHttpClient.<clinit>(AmazonHttpClient.java:165) ~[aws-java-sdk-core-1.12.687.jar:?]",
"\tat com.amazonaws.AmazonWebServiceClient.<init>(AmazonWebServiceClient.java:236) ~[aws-java-sdk-core-1.12.687.jar:?]",
"\tat com.amazonaws.AmazonWebServiceClient.<init>(AmazonWebServiceClient.java:225) ~[aws-java-sdk-core-1.12.687.jar:?]",
"\tat com.amazonaws.services.securitytoken.AWSSecurityTokenServiceClient.<init>(AWSSecurityTokenServiceClient.java:299) ~[aws-java-sdk-sts-1.12.687.jar:?]",
"\tat com.amazonaws.services.securitytoken.AWSSecurityTokenServiceClient.<init>(AWSSecurityTokenServiceClient.java:285) ~[aws-java-sdk-sts-1.12.687.jar:?]",
"\tat com.amazonaws.services.securitytoken.AWSSecurityTokenServiceClientBuilder.build(AWSSecurityTokenServiceClientBuilder.java:61) ~[aws-java-sdk-sts-1.12.687.jar:?]",
"\tat com.amazonaws.services.securitytoken.AWSSecurityTokenServiceClientBuilder.build(AWSSecurityTokenServiceClientBuilder.java:27) ~[aws-java-sdk-sts-1.12.687.jar:?]",
"\tat com.amazonaws.client.builder.AwsSyncClientBuilder.build(AwsSyncClientBuilder.java:46) ~[aws-java-sdk-core-1.12.687.jar:?]",
"\tat org.opensearch.notifications.core.credentials.oss.CredentialsProviderFactory.getCredentialsProviderByIAMRole(CredentialsProviderFactory.kt:30) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"\tat org.opensearch.notifications.core.credentials.oss.CredentialsProviderFactory.getCredentialsProvider(CredentialsProviderFactory.kt:20) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"\tat org.opensearch.notifications.core.credentials.oss.SesClientFactoryImpl.createSesClient$lambda$0(SesClientFactoryImpl.kt:19) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"\tat java.base/java.security.AccessController.doPrivileged(AccessController.java:571) ~[?:?]",
"\tat org.opensearch.notifications.core.utils.SecurityAccess.doPrivileged(SecurityAccess.kt:25) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"\tat org.opensearch.notifications.core.credentials.oss.SesClientFactoryImpl.createSesClient(SesClientFactoryImpl.kt:17) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"\tat org.opensearch.notifications.core.client.DestinationSesClient.sendMimeMessage(DestinationSesClient.kt:88) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"\tat org.opensearch.notifications.core.client.DestinationSesClient.execute(DestinationSesClient.kt:74) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"\tat org.opensearch.notifications.core.transport.SesDestinationTransport.sendMessage(SesDestinationTransport.kt:43) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"\tat org.opensearch.notifications.core.transport.SesDestinationTransport.sendMessage(SesDestinationTransport.kt:23) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"\tat org.opensearch.notifications.core.NotificationCoreImpl.sendMessage$lambda$0(NotificationCoreImpl.kt:38) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"\tat java.base/java.security.AccessController.doPrivileged(AccessController.java:319) ~[?:?]",
"\tat org.opensearch.notifications.core.NotificationCoreImpl.sendMessage(NotificationCoreImpl.kt:35) ~[opensearch-notifications-core-3.1.0.0.jar:3.1.0.0]",
"\tat org.opensearch.notifications.send.SendMessageActionHelper.sendMessageThroughSpi(SendMessageActionHelper.kt:598) ~[?:?]",
"\tat org.opensearch.notifications.send.SendMessageActionHelper.sendEmailFromSesAccount(SendMessageActionHelper.kt:566) ~[?:?]",
"\tat org.opensearch.notifications.send.SendMessageActionHelper.access$sendEmailFromSesAccount(SendMessageActionHelper.kt:63) ~[?:?]",
"\tat org.opensearch.notifications.send.SendMessageActionHelper$sendEmailMessage$1$statusDeferredList$1$1.invokeSuspend(SendMessageActionHelper.kt:479) ~[?:?]",
"\tat kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33) [kotlin-stdlib-1.9.25.jar:1.9.25-release-852]",
"\tat kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106) [kotlinx-coroutines-core-jvm-1.4.3.jar:?]",
"\tat kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:571) [kotlinx-coroutines-core-jvm-1.4.3.jar:?]",
"\tat kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:750) [kotlinx-coroutines-core-jvm-1.4.3.jar:?]",
"\tat kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:678) [kotlinx-coroutines-core-jvm-1.4.3.jar:?]",
"\tat kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:665) [kotlinx-coroutines-core-jvm-1.4.3.jar:?]",
"Caused by: java.lang.ClassNotFoundException: org.apache.http.conn.routing.HttpRoutePlanner",
"\tat java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:445) ~[?:?]",
"\tat java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:593) ~[?:?]",
"\tat java.base/java.net.FactoryURLClassLoader.loadClass(URLClassLoader.java:872) ~[?:?]",
"\tat java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:526) ~[?:?]",
"\t... 31 more",
"Caused by: java.lang.ExceptionInInitializerError: Exception java.lang.NoClassDefFoundError: org/apache/http/conn/routing/HttpRoutePlanner [in thread \"DefaultDispatcher-worker-2\"]",
"at com.amazonaws.http.AmazonHttpClient.<clinit>(AmazonHttpClient.java:165) ~[?:?]",
"... 30 more"] }
java.lang.NoClassDefFoundError: Could not initialize class com.amazonaws.http.AmazonHttpClient
        at com.amazonaws.AmazonWebServiceClient.<init>(AmazonWebServiceClient.java:236)
        at com.amazonaws.AmazonWebServiceClient.<init>(AmazonWebServiceClient.java:225)
        at com.amazonaws.services.securitytoken.AWSSecurityTokenServiceClient.<init>(AWSSecurityTokenServiceClient.java:299)
        at com.amazonaws.services.securitytoken.AWSSecurityTokenServiceClient.<init>(AWSSecurityTokenServiceClient.java:285)
        at com.amazonaws.services.securitytoken.AWSSecurityTokenServiceClientBuilder.build(AWSSecurityTokenServiceClientBuilder.java:61)
        at com.amazonaws.services.securitytoken.AWSSecurityTokenServiceClientBuilder.build(AWSSecurityTokenServiceClientBuilder.java:27)
        at com.amazonaws.client.builder.AwsSyncClientBuilder.build(AwsSyncClientBuilder.java:46)
        at org.opensearch.notifications.core.credentials.oss.CredentialsProviderFactory.getCredentialsProviderByIAMRole(CredentialsProviderFactory.kt:30)
        at org.opensearch.notifications.core.credentials.oss.CredentialsProviderFactory.getCredentialsProvider(CredentialsProviderFactory.kt:20)
        at org.opensearch.notifications.core.credentials.oss.SesClientFactoryImpl.createSesClient$lambda$0(SesClientFactoryImpl.kt:19)
        at java.base/java.security.AccessController.doPrivileged(AccessController.java:571)
        at org.opensearch.notifications.core.utils.SecurityAccess.doPrivileged(SecurityAccess.kt:25)
        at org.opensearch.notifications.core.credentials.oss.SesClientFactoryImpl.createSesClient(SesClientFactoryImpl.kt:17)
        at org.opensearch.notifications.core.client.DestinationSesClient.sendMimeMessage(DestinationSesClient.kt:88)
        at org.opensearch.notifications.core.client.DestinationSesClient.execute(DestinationSesClient.kt:74)
        at org.opensearch.notifications.core.transport.SesDestinationTransport.sendMessage(SesDestinationTransport.kt:43)
        at org.opensearch.notifications.core.transport.SesDestinationTransport.sendMessage(SesDestinationTransport.kt:23)
        at org.opensearch.notifications.core.NotificationCoreImpl.sendMessage$lambda$0(NotificationCoreImpl.kt:38)
        at java.base/java.security.AccessController.doPrivileged(AccessController.java:319)
        at org.opensearch.notifications.core.NotificationCoreImpl.sendMessage(NotificationCoreImpl.kt:35)
        at org.opensearch.notifications.send.SendMessageActionHelper.sendMessageThroughSpi(SendMessageActionHelper.kt:598)
        at org.opensearch.notifications.send.SendMessageActionHelper.sendEmailFromSesAccount(SendMessageActionHelper.kt:566)
        at org.opensearch.notifications.send.SendMessageActionHelper.access$sendEmailFromSesAccount(SendMessageActionHelper.kt:63)
        at org.opensearch.notifications.send.SendMessageActionHelper$sendEmailMessage$1$statusDeferredList$1$1.invokeSuspend(SendMessageActionHelper.kt:479)
        at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
        at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
        at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:571)
        at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:750)
        at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:678)
        at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:665)
        Suppressed: java.lang.NoClassDefFoundError: Could not initialize class com.amazonaws.http.AmazonHttpClient
                ... 30 more
        Caused by: java.lang.ExceptionInInitializerError: Exception java.lang.NoClassDefFoundError: org/apache/http/conn/routing/HttpRoutePlanner [in thread "DefaultDispatcher-worker-2"]
                at com.amazonaws.http.AmazonHttpClient.<clinit>(AmazonHttpClient.java:165)
                ... 30 more
        Suppressed: java.lang.NoClassDefFoundError: org/apache/http/conn/routing/HttpRoutePlanner
                at com.amazonaws.http.AmazonHttpClient.<clinit>(AmazonHttpClient.java:165)
                ... 30 more
        Caused by: java.lang.ClassNotFoundException: org.apache.http.conn.routing.HttpRoutePlanner
                at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:445)
                at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:593)
                at java.base/java.net.FactoryURLClassLoader.loadClass(URLClassLoader.java:872)
                at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:526)
                ... 31 more
Caused by: [CIRCULAR REFERENCE: java.lang.ExceptionInInitializerError: Exception java.lang.NoClassDefFoundError: org/apache/http/conn/routing/HttpRoutePlanner [in thread "DefaultDispatcher-worker-2"]]

How can one reproduce the bug?
Steps to reproduce the behavior:

1. Setup and activate a notification via SES sender (I've used snapshot management notifications)
2. Wait till snapshot being created OR press Send test message on Notification channels / Channels page
3. See error in dead node log

What is the expected behavior?
A clear and concise description of what you expected to happen.

What is your host/environment?

• OS: Linux
• Version: 3.1.0
• Plugins:

opensearch-alerting                  3.1.0.0
opensearch-anomaly-detection         3.1.0.0
opensearch-asynchronous-search       3.1.0.0
opensearch-cross-cluster-replication 3.1.0.0
opensearch-custom-codecs             3.1.0.0
opensearch-flow-framework            3.1.0.0
opensearch-geospatial                3.1.0.0
opensearch-index-management          3.1.0.0
opensearch-job-scheduler             3.1.0.0
opensearch-knn                       3.1.0.0
opensearch-ltr                       3.1.0.0
opensearch-ml                        3.1.0.0
opensearch-neural-search             3.1.0.0
opensearch-notifications             3.1.0.0
opensearch-notifications-core        3.1.0.0
opensearch-observability             3.1.0.0
opensearch-performance-analyzer      3.1.0.0
opensearch-reports-scheduler         3.1.0.0
opensearch-search-relevance          3.1.0.0
opensearch-security                  3.1.0.0
opensearch-security-analytics        3.1.0.0
opensearch-skills                    3.1.0.0
opensearch-sql                       3.1.0.0
opensearch-system-templates          3.1.0.0
opensearch-ubi                       3.1.0.0
query-insights                       3.1.0.0
repository-s3                        3.1.0

Do you have any screenshots?
No.

Do you have any additional context?
In #1020 both dependencies org.apache.httpcomponents:httpclient:4.5.14 and org.apache.httpcomponents.client5:httpclient5:5.4.2 were added, and I suspect that latter may not be compartible with AWS SDK v1.x

[SammyROCK]

I'm suffering from this issue.
After an upgraded from v2.19.1 to v3.1.0, my nodes started to crash every time a monitor would trigger a SNS notification.
I had to disable the notification plugin to get it running again.

[SammyROCK]

I updated my server to v3.2.0
It's running under Ubuntu 22.04.5 LTS (GNU/Linux 6.8.0-1035-aws aarch64) on ARM
The server does not crash as long as there is no trigger on SNS

When I try sending a test message through SNS, my OpenSearch instance crashes with the following error in opensearch.log

[2025-08-22T02:26:14,776][ERROR][o.o.b.OpenSearchUncaughtExceptionHandler] [ip-172-31-49-254] fatal error in thread [DefaultDispatcher-worker-2], exiting
java.lang.NoClassDefFoundError: org/apache/http/protocol/HttpRequestExecutor
        at com.amazonaws.http.AmazonHttpClient.<clinit>(AmazonHttpClient.java:165) ~[aws-java-sdk-core-1.12.687.jar:?]
        at com.amazonaws.AmazonWebServiceClient.<init>(AmazonWebServiceClient.java:236) ~[aws-java-sdk-core-1.12.687.jar:?]
        at com.amazonaws.AmazonWebServiceClient.<init>(AmazonWebServiceClient.java:225) ~[aws-java-sdk-core-1.12.687.jar:?]
        at com.amazonaws.services.securitytoken.AWSSecurityTokenServiceClient.<init>(AWSSecurityTokenServiceClient.java:299) ~[aws-java-sdk-sts-1.12.687.jar:?]
        at com.amazonaws.services.securitytoken.AWSSecurityTokenServiceClient.<init>(AWSSecurityTokenServiceClient.java:285) ~[aws-java-sdk-sts-1.12.687.jar:?]
        at com.amazonaws.services.securitytoken.AWSSecurityTokenServiceClientBuilder.build(AWSSecurityTokenServiceClientBuilder.java:61) ~[aws-java-sdk-sts-1.12.687.jar:?]
        at com.amazonaws.services.securitytoken.AWSSecurityTokenServiceClientBuilder.build(AWSSecurityTokenServiceClientBuilder.java:27) ~[aws-java-sdk-sts-1.12.687.jar:?]
        at com.amazonaws.client.builder.AwsSyncClientBuilder.build(AwsSyncClientBuilder.java:46) ~[aws-java-sdk-core-1.12.687.jar:?]
        at org.opensearch.notifications.core.credentials.oss.CredentialsProviderFactory.getCredentialsProviderByIAMRole(CredentialsProviderFactory.kt:30) ~[opensearch-notifications-core-3.2.0.0.jar:3.2.0.0]
        at org.opensearch.notifications.core.credentials.oss.CredentialsProviderFactory.getCredentialsProvider(CredentialsProviderFactory.kt:20) ~[opensearch-notifications-core-3.2.0.0.jar:3.2.0.0]
        at org.opensearch.notifications.core.credentials.oss.SnsClientFactoryImpl.createSnsClient$lambda$0(SnsClientFactoryImpl.kt:20) ~[opensearch-notifications-core-3.2.0.0.jar:3.2.0.0]
        at java.base/java.security.AccessController.doPrivileged(AccessController.java:251) ~[?:?]
        at org.opensearch.notifications.core.utils.SecurityAccess.doPrivileged(SecurityAccess.kt:25) ~[opensearch-notifications-core-3.2.0.0.jar:3.2.0.0]
        at org.opensearch.notifications.core.credentials.oss.SnsClientFactoryImpl.createSnsClient(SnsClientFactoryImpl.kt:18) ~[opensearch-notifications-core-3.2.0.0.jar:3.2.0.0]
        at org.opensearch.notifications.core.client.DestinationSnsClient.execute(DestinationSnsClient.kt:48) ~[opensearch-notifications-core-3.2.0.0.jar:3.2.0.0]
        at org.opensearch.notifications.core.transport.SnsDestinationTransport.sendMessage(SnsDestinationTransport.kt:41) ~[opensearch-notifications-core-3.2.0.0.jar:3.2.0.0]
        at org.opensearch.notifications.core.transport.SnsDestinationTransport.sendMessage(SnsDestinationTransport.kt:21) ~[opensearch-notifications-core-3.2.0.0.jar:3.2.0.0]
        at org.opensearch.notifications.core.NotificationCoreImpl.sendMessage$lambda$0(NotificationCoreImpl.kt:38) ~[opensearch-notifications-core-3.2.0.0.jar:3.2.0.0]
        at java.base/java.security.AccessController.doPrivileged(AccessController.java:74) ~[?:?]
        at org.opensearch.notifications.core.NotificationCoreImpl.sendMessage(NotificationCoreImpl.kt:35) ~[opensearch-notifications-core-3.2.0.0.jar:3.2.0.0]
        at org.opensearch.notifications.send.SendMessageActionHelper.sendMessageThroughSpi(SendMessageActionHelper.kt:598) ~[?:?]
        at org.opensearch.notifications.send.SendMessageActionHelper.sendSNSMessage(SendMessageActionHelper.kt:584) ~[?:?]
        at org.opensearch.notifications.send.SendMessageActionHelper.sendMessageToChannel(SendMessageActionHelper.kt:250) ~[?:?]
        at org.opensearch.notifications.send.SendMessageActionHelper.access$sendMessageToChannel(SendMessageActionHelper.kt:63) ~[?:?]
        at org.opensearch.notifications.send.SendMessageActionHelper$sendMessagesInParallel$1$statusDeferredList$1$1.invokeSuspend(SendMessageActionHelper.kt:160) ~[?:?]
        at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33) [kotlin-stdlib-1.9.25.jar:1.9.25-release-852]
        at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106) [kotlinx-coroutines-core-jvm-1.4.3.jar:?]
        at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:571) [kotlinx-coroutines-core-jvm-1.4.3.jar:?]
        at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:750) [kotlinx-coroutines-core-jvm-1.4.3.jar:?]
        at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:678) [kotlinx-coroutines-core-jvm-1.4.3.jar:?]
        at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:665) [kotlinx-coroutines-core-jvm-1.4.3.jar:?]
Caused by: java.lang.ClassNotFoundException: org.apache.http.protocol.HttpRequestExecutor
        at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:349) ~[?:?]
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:557) ~[?:?]
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:490) ~[?:?]
        ... 31 more